My dealer believes that one can use 500E springs/ shocks in a 400E.
Any thoughts about the accuracy of this ???
Also, would this increase the performance of the 400E more than that obtained by simply using H&R springs with Bilstein Sport shocks ?
If so, would this solution be cost-effective, namley if the 500E parts cost orders of magnitude more than aftermarkets, while providing marginal performance improvement, then one might reason that the solution is not cost-effective :-)
thanks
farrukh

I would think that unless your specific model 400E/E420 has the (rare as hell on a 4.2 W124) self-leveling option the swap would not be viable. Even so, for what 500E stuff would cost you are better off going tuner. That would give you something specifically optimized for your car's attributes.

Hope this helps...Lee